1. Field of Invention
The invention relates generally to instruments for examining and treating the eye and specifically to a scanning laser opthalmoscope (SLO) based on a relaxed confocal catadioptric design, in combination with various external light sources, and optimized for advanced non-invasive diagnostic procedures, optical coherence tomography (OCT) and microperimetry (MP).
2. Description of Prior Art
The opthalmoscope is well known as an important device for examining the eye, and in particular the retina. As a result of great interest in preserving eyesight, opthalmoscopes of various constructions have been built. The latest version of the opthalmoscope, a scanning laser opthalmoscope, is particularly appealing because of its unique capability of combining a high resolution and high contrast infra-red or angiographic 60 Hz interlaced video imaging of the retina with psychophysical procedures such as microperimetry. A precise correlation between retinal anatomy and retinal functioning can be established with the scanning laser opthalmoscope. This retinal function mapping that includes information about fixation characteristics, visual acuity and retinal sensitivity, is now known to be very helpful to the surgeon when applying various forms of therapeutic laser and for the purpose of low vision rehabilitation. Van de Velde has disclosed before in U.S. Pat. Nos. 5,892,569, 5,923,399, 5,943,117, 6,186,628 and 6,789,900, which are all herein incorporated by reference, different embodiments of the relaxed confocal scanning laser opthalmoscope that use various external light sources for therapeutic and diagnostic applications. Such functional extensions of the basic instrument rely to a great extent on its relaxed confocal and catadioptric design, incorporating one or two synchronized avalanche photodetector pathways.
Additional extended functionality has been disclosed in the U.S. Pat. Nos. 5,543,866, 5,568,208 and 6,000,799, herein incorporated by reference. Such embodiments have been constructed and the results have been reported in the following publications, that are herein incorporated by reference:    1. Frans J. Van de Velde. Quantitative SLO microperimetry for clinical research in age related maculopathy. In: Noninvasive assessment of the visual system: from the Topical Meeting Vision Science and its Applications, Jan. 31-Feb. 3, 1997, Santa Fe, N. Mex./edited by Dean Yager; sponsored by Optical Society of America; in cooperation with the American Academy of Optometry. Published/Created: Washington, D.C.: The Society, 1997: 42-47. ISBN: 1557524718 (Library of Congress).    2. Frans J. Van de Velde. Role of the scanning laser opthalmoscope in photodynamic therapy of macular disease Publication: Proc. SPIE Vol. 3908, p. 190-201, Ophthalmic Technologies X; Pascal O. Rol, Karen M. Joos, Fabrice Manns; Eds. Publication date: June 2000.    3. Frans J. Van de Velde. Scanning laser opthalmoscope optimized for retinal microphotocoagulation. Publication: Proc. SPIE Vol. 3564, p. 146-157, Medical Applications of Lasers in Dermatology, Cardiology, Opthalmology, and Dentistry II; Gregory B. Altshuler, Stefan Andersson-Engels, Reginald Birngruber, Peter Bjerring, Adolf F. Fercher, Herbert J. Geschwind, Raimund Hibst, Herbert Hoenigsmann, Frederic Laffitte, Henricus J. Sterenborg; Eds. Publication date: February 1999.    4. Frans J. Van de Velde et Al. Scanning laser retinoscopy: a new technique for evaluating optical properties of the cornea after refractive surgery Publication: Proc. SPIE Vol. 3192, p. 187-194, Medical Applications of Lasers in Dermatology, Opthalmology, Dentistry, and Endoscopy; Gregory B. Altshuler, Reginald Birngruber, Marco Dal Fante, Raimund Hibst, Herbert Hoenigsmann, Neville Krasner, Frederic Laffitte; Eds. Publication date: December 1997.    5. Frans J. Van de Velde. Scanning laser opthalmoscopy: optimized testing strategies for psychophysics Publication: Proc. SPIE Vol. 2930, p. 79-90, Lasers in Opthalmology IV; Reginald Birngruber, Adolf F. Fercher, Philippe Sourdille; Eds. Publication date: December 1996.